The Rare Fruit of the Kazook Tree is a rare and expensive yet small fruit that only appears in the episode "Le Big Switch."
The fruit has a strong rancid smell, yet is still expensive, as it costs $52, and it needs literal shredded gold as an ingredient to neutralize its awful scent. It does not look like a traditional fruit, rather a small flat cylinder made up of some beans, rice, or some other sort of grain. It has one small leaf sticking up out of it. It is unknown if it is part of the fruit or if it is put there simply for decoration.
The Rare Fruit of the Kazook Tree is based on the real-life Durian fruit, which has a smell that is said to resemble rotten eggs and gym socks.